Execution is more important than an idea. "Facebook too wasn’t a new idea but I think we took the idea and we focused on execution, focused on quality and getting to scale," D'Angelo told Malik. "Similarly for Quora, we want to get to be 100 times bigger than we are today."

Get comfortable giving up control. "At Facebook [and at Quora] I went from coding to management," he says. "You have to get comfortable giving up control, and you find people who do things better than you do. Quora now does better with the team we have built."

But most of all: "Focus on the long term, and always do what’s right to grow the company and not make short-term decisions. And outlast everyone one."